Computing devices such as personal computers, laptop computers, tablet computers, cellular phones, and countless types of Internet-capable devices are increasingly prevalent in numerous aspects of modem life. As such, the demand for data connectivity via the Internet, cellular data networks, and other such networks, is growing. However, there are many areas of the world where data connectivity is still unavailable, or if available, is unreliable and/or costly. Accordingly, additional network infrastructure is desirable.
Some systems may provide network access via a balloon network operating in the stratosphere. Because of the various forces experienced by these balloons during deployment and operation, there is a balancing of needs between flexibility and stability of materials. The balloons may be made of an envelope material configured in sections or lobes to create a “pumpkin” or lobed balloon. The lobes are supported by a plurality of tendons.
Before a balloon can be deployed, the balloon envelope must be inflated with lighter than air lift gases, such as helium, hydrogen or other types of gases. As an example, an interface, such as a small fill tube, may be attached to a top plate on the balloon and coupled to a filling hose for filling the envelope with gas. However, this interface is often prone to leaking and the top plate can sag or can otherwise become prolapsed into the balloon, thereby possibly causing damage to the balloon envelope, if there is not sufficient pressure at the top of the balloon to support the plate's weight.